Effect of Substrate Preheating on Bonding Strength of Cold-Sprayed Mg Coatings
- PDF / 931,161 Bytes
- 8 Pages / 593.972 x 792 pts Page_size
- 96 Downloads / 194 Views
.K. Suo, M. Yu, W.Y. Li, M.P. Planche, and H.L. Liao (Submitted March 5, 2012; in revised form June 4, 2012) A poor bonding strength between the magnesium coating and substrate limits magnesium coatings application. This paper aims at improving the bonding strength between the coating and substrate using substrate preheating. Aluminum substrates were heated to 100, 200 and 300 °C by a flame nozzle prior to cold spraying. The effects of substrate preheating on the microstructure and bonding strength were studied. The deformation behavior of single particles was simulated by a commercial software ABAQUS, and observed using SEM. The results show that substrate preheating can increase the bonding strength significantly. The bonding strength increased from 3.3 ± 0.8 to 11.6 ± 0.5 MPa when the substrate temperature increased from room-temperature to 200 °C. The fracture analyses show that the coating fracture occurred within the coating when the substrate was preheated at 200 °C.
Keywords
bonding strength, cold spraying, magnesium coating, substrate preheating
1. Introduction Cold spraying, as an emerging coating process, has attracted worldwide interest for its high deposition efficiency and volume production of many metallic coatings (Ref 1-4), composites (Ref 5-7). Moreover, cermet coatings (Ref 8) have been deposited by cold spraying. In this process, spray particles (typically 5-100 lm) are accelerated to a high velocity by a high-speed gas jet generated through a convergent-divergent type nozzle. A coating is formed through the intensive plastic deformation of particles impacting on a substrate at a temperature well below the melting point of the spray material. Therefore, cold spraying can be used to elaborate a coating made of easily oxidized material. Cold sprayed magnesium (Mg) coatings are becoming an interesting and attractive program, on one hand because Mg has the highest strength to weight ratio among all metallic structural materials, which offers potential applications in aerospace industry (Ref 9), on the other X.K. Suo, M.P. Planche, and H.L. Liao, LERMPS, Universite´ de Technologie de Belfort-Montbe´liard, Site de Se´venans, 90010 Belfort Cedex, France; M. Yu, LERMPS, Universite´ de Technologie de Belfort-Montbe´liard, Site de Se´venans, 90010 Belfort Cedex, France; and State Key Laboratory of Solidification Processing, Shaanxi Key Laboratory of Friction Welding Technologies, Northwestern Polytechnical University, Xian 710072, Shaanxi Peoples Republic of China; and and W.Y. Li, State Key Laboratory of Solidification Processing, Shaanxi Key Laboratory of Friction Welding Technologies, Northwestern Polytechnical University, Xian 710072, Shaanxi Peoples Republic of China. Contact e-mail: suoxinkun@gmail. com.
Journal of Thermal Spray Technology
hand because cold spraying can elaborate Mg coatings efficiently without oxidation or deterioration. In the previous studies (Ref 10, 11), Mg coatings with a low porosity and high microhardness were fabricated on stainless steel and aluminum substrates by
Data Loading...
